1. Field of the Invention
The present invention relates to a method of designing centrifugal and mixed flow pumps having a specific speed of 150 to 1200, and more particularly, to a pump designing method of setting design variables for designing an impeller, automatically calculating meridional plane information of the impeller from design variable values when the design variable values are input, deriving a vane angle of the impeller from the calculated meridional plane information, and generating a three-dimensional (3D) shape of the impeller, which provides an optimal design of the 3D shape of the impeller by converting tendencies of the design variables of the impeller according to specific speed into functions and turning the tendencies into a database (D/B), more specifically, builds a design D/B for optimizing meridional plane and vane angle distribution shape variables according to specific speed (150 to 1200 Ns) and develops a design program making use of the design D/B to facilitate 3D design of an impeller.
2. Discussion of Related Art
In general, to present a 3D shape of an impeller, there is a necessity for a design program to automatically calculate meridional plane information for the impeller from a design variable for designing the impeller that is set and input and calculate vane angle information of the impeller using the calculated meridional plane information.
Most design programs for centrifugal and mixed flow pumps are foreign products developed based on theories and empirical formulas. Due to being designs based on theories and empirical formulas, the designed shapes are simple. Therefore, when a customer requires high performance, there is inconvenience of having to go through an optimal design operation again.
Also, it is complicated to use the foreign developed design programs and the design programs can only be used by a user with professional knowledge and theories. For this reason, it is difficult for a beginner of pump designing to use the foreign design programs.
As an example, in “CF turbo” which is a representative German pump designing program, traditional German design techniques for pumps, fans, compressors, turbines, turbochargers, and other turbomachines are combined with high-tech software engineering. Due to being a design method based on theories and empirical formulas, the designed shaped are simple, and re-designing is necessary to design a pump having specifications required by a customer.
As another example, “VISTA” developed by PCA in the UK is a program for designing a vane shape when a designer inputs fluid conditions, compressor duty and aerodynamic data, and specific geometry constraints. VISTA is relatively easy to use, and also the designed shapes are simple. By using through-flow calculation as an optimal design method, many design variables can be taken into consideration, but the reliability of interpretation is relatively low.
As still another example, “Concepts NREC” of the USA is a program in which several pieces of software for efficiently designing, interpreting, and manufacturing turbomachines (a pump, a fan, a compressor, and a turbine) widely used throughout industries are integrated. The integrated design-interpretation-manufacturing program makes it possible to simply design a turbomachine, but it is difficult to achieve high performance (high efficiency and strong suction).
Consequently, there is an urgent need to develop a technology for designing centrifugal and mixed flow pumps.